离子化程度对硼取代富勒烯C19Bn+(n=0-3)体系储氢性能的影响

Ionization-degree induced hydrogen storage by boron substituted fullerene C19Bn+(n=0-3)

本文采用密度泛函理论方法,研究了氢气分子在硼取代富勒烯C19Bn+(n=0-3)表面的非解离吸附态、化学吸附态、及吸附态之间转换过渡态的结构和能量,得到了吸附态之间转换反应的势能面.研究表明通过调整体系的离子化电荷可以调整吸附位点的电荷布居数,随着硼取代富勒烯离子化体系C19Bn+的吸氢活性位点电荷布居数增大,氢分子被极化的程度以及氢分子在材料表面的吸附能均逐渐增大,同时改变电荷布居数也对氢气分子在表面吸附态间转变势垒高度产生了量级为几个Kcal/mol的影响.希望我们的研究能够对富勒烯储氢的进一步发展提供参考.

In this paper,the density functional theory method is used to study the structures and energiesthe non-dissociative adsorption state,chemical adsorption state,and the transition state transformation from the non-dissociative adsorption state to chemical adsorption state,for the system of hydrogen molecules on the surface of boron substituted fullerene C19Bn+(n=0-3).The potential energy surface(PES)of the conversion reaction between the two adsorption states is obtained.Studies have shown that by adjusting the ionization charge of the system,the population of the charged sites can be adjusted.As the number of charged sites on the hydrogen-absorbing active sites of the C19Bn+ionized by boron-substituted fullerenes increases,the hydrogen molecules are polarized.The degree of adsorption of hydrogen molecules on the surface of the material is gradually increasing,while changing the charge population also has an effect of several Kcal/mol on the height of the transition barrier between the two states of hydrogen molecules adsorbed on the surface.We hope that our research can provide a reference for the further development of fullerene hydrogen storage.